Hydrogen is a high-efficiency and clean secondary energy source with the advantages of high combustion value, abundant resources and renewability. Hence, the desirability of generating and utilizing hydrogen has been widely recognized by countries all over the world. There are many preparation methods for hydrogen, including hydrogen production using fossil energy (where natural gas or methane is passed through a special reformer which reacts steam at high temperature to obtain the hydrogen), as an industrial by-product and by water electrolysis. Water electrolysis is an easy-to-operate hydrogen production process, resulting in a purity of hydrogen high enough for electrolysis to be widely used in the industry. In recent years, the utilization of renewable energy sources has been promoted to address the serious environmental pollution problems associated with fossil energy sources. Hydrogen production by water electrolysis has become an important task as a large amount of wind and hydropower resources cannot be integrated into electricity generation.
Although hydrogen production technology for water electrolysis has been widely used in the industry, the electric energy consumption for hydrogen evolution is large and energy transformation efficiency is low due to the increase of cell voltage during the process of water electrolysis. Currently, in the alkaline water electrolysis industry, the material used in the cathode during the hydrogen evolution process is nickel. However, the overpotential of hydrogen evolution is high, reaching 480 mV. In order to render alkaline water electrolysis more suitable for widespread use in hydrogen production, it is desirable to reduce the electricity consumption during the process of water electrolysis.
Porous nickel catalytic material has been researched for a long time, and various nickel-based electrodes have been developed. For example, U.S. Pat. No. 4,447,302A describes a porous electrode, hot pressed from nickel powder for alkaline water electrolysis, which is alloyed with 1-15% by weight of titanium, a precious metal. Further, Ragunathan et al. describe a method for preparing porous nickel electrodes by repeated spray coating, drying and pressing the nickel mix, and then sintering in a hydrogen atmosphere under 900-1000° C. (“Porous nickel electrodes in water electrolysis 1. Electrode preparation and polarization studies in strong alkali,” International Journal of Hydrogen Energy, Volume 6, Issue 5, 1981, Pages 487-496). In this research, the nickel mix consists of fine carbonyl nickel powder, nickel oxalate and methyl cellulose suspended in water, forming a thin paste. These and many other prior-art approaches make use of expensive raw materials, and increase the complexity of the preparation process.